The RFID tag is used in various fields. In addition, a communication system between the RFID tag and a tag reader or a tag writer includes an electromagnetic induction system and a radio wave system. The RFID tag may be mounted on a curved surface, a metal surface, or the like. In a case in which the RFID tag is mounted on the curved surface, a core of the RFID is desirably formed by an elastic material.
On the other hand, in a case in which the radio wave system RFID is mounted on the metal surface, a communication distance communicable between the RFID tag and the tag reader or the tag writer can be improved by forming an antenna in a loop shape. However, in a case in which when mounting the RFID tag on an inner side or an outer side of a metal pipe having a relatively small diameter, for example, it is difficult to form the loop-shaped antenna part to have a suitable elasticity, even when the core of the RFID tag is formed by the elastic material. For this reason, as a radius of curvature of the curved surface becomes smaller, wrinkles or cracks may be formed at the loop-shaped antenna part of the RFID tag, and in a worst case, the RFID tag is broken or damaged. In addition, in a case in which the RFID tag is adhered on the curved surface using an adhesive tape or the like, the smaller the radius or curvature of the curves surface, the easier the mounted RFID tag separates from the adhered curved surface, because it is difficult to form the loop-shaped antenna part to have the suitable elasticity.
The curved surface may include a plurality of concave parts and convex parts, or a plurality of concave parts or convex parts having different radii of curvature. In these cases, it is also difficult to mount the RFID tag having the loop-shaped antenna on the curved surface.
Hence, the conventional RFID tag having the loop-shaped antenna is unsuited for mounting on the curved surface.
Related art may include Japanese Laid-Open Patent Publications No. 2006-53833, No. 2011-109552, and No. 2008-90813, for example.